Kingsley,

 

Actually.  ARP ACL's do not work in conjunction with Snooping.  They are
specifically for environments without DHCP.  The DHCP snooping database is
not checked as a precursor to the ACL.

 

Regards,

 

Tyson Scott - CCIE #13513 R&S, Security, and SP

Technical Instructor - IPexpert, Inc.

Mailto: [email protected]

Telephone: +1.810.326.1444, ext. 208

Live Assistance, Please visit: www.ipexpert.com/chat

eFax: +1.810.454.0130

 

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From: [email protected]
[mailto:[email protected]] On Behalf Of Kingsley
Charles
Sent: Wednesday, March 31, 2010 8:11 AM
To: [email protected]
Subject: [OSL | CCIE_Security] ARP access-list with static

 

Hi all

 

As any other access-list, arp access-list also has an implicit deny any any
at the end and hence, even if there is a dhcp snooping entry, the ARP packet
will be dropped, if there is no entry in the access-list. As per the notes
from Cisco given below, the implicit deny deny will be activated only when
the "static" keyword is configured.

 

I have a arp access-list with no entry and have applied to the vlan.

 

Even without the "static" keyword, the ARP packets are dropped though I have
a dhcp snooping binding available.

 

Any thoughts?

 

 

 

 

ip arp inspection filter vlan 

To permit ARPs from hosts that are configured for static IP when DAI is
enabled and to define an ARP access list and apply it to a VLAN, use the ip
arp inspection filter vlan command in global configuration mode. To disable
this application, use the no form of this command. 

ip arp inspection filter arp-acl-name vlan vlan-range [static] 

no ip arp inspection filter arp-acl-name vlan vlan-range [static] 

Syntax Description 


 

        


arp-acl-name 

Access control list name. 


vlan-range 

VLAN number or range; valid values are from 1 to 4094. 


static 

(Optional) Treats implicit denies in the ARP ACL as explicit denies and
drops packets that do not match any previous clauses in the ACL

 

 

With regards

Kings

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